Tile for removing formaldehyde and process for preparing the same

ABSTRACT

A tile using an activated carbon, which is excellent as a formaldehyde absorbent, and a preparation process thereof are disclosed. The effect of activated carbon on absorbing formaldehyde is maximized by the activated carbon-in-core structure, in which the problem of activated carbon that is easily oxidized during a heat treatment may be overcome.

TECHNICAL FIELD

The present invention relates to a functional tile and a process forpreparing the same, and more particularly to a tile for removingformaldehyde and a process for preparing the same.

BACKGROUND ART

As an absorbent added in the production of a functional tile forremoving formaldehyde using loess or clay, use can be made of variousmaterials such as charcoals, zeolites, diatomites, or ashes.

In connection to the above, Korean Patent Laid-open Publication No.2001-49437 discloses a building material and room using allophane,Korean Patent Registration No. 495571 discloses a healthy tile using flyash and diatomite, Korean Patent Registration No. 478949 discloses aprocess for producing an earthen vessel containing charcoal using woodflour, Korean Patent Registration No. 301253 discloses a wallboardhaving a humidity function and a manufacturing method thereof, KoreanPatent Registration No. 677761 discloses functional building materialsand a method for production thereof, and Japanese Patent Laid-openPublication No. 2006-248793 discloses a tile material for construction.There are other various techniques in relation therewith, but none hasbeen described of an activated carbon constituting the core according tothe present invention and improvement in formaldehyde absorptionperformance using the same.

The most important factor for improving formaldehyde removal performanceof a functional tile is the performance of an absorbent itself However,when including the absorbent to actually exert its function, there maybe concerns of deterioration and reduced performance of the absorbentitself due to the heat treatment in the preparation process of the tile.Therefore, an ideal tile for removing formaldehyde results from atechnique that is capable of maximizing the realization of the initialperformance of the absorbent.

DISCLOSURE Technical Problem

Therefore, the present invention has been made in view of the aboveproblems, and it is an object of the present invention to provide a tilewhich can realize a maximum absorption performance of an activatedcarbon by including the activated carbon with excellent formaldehydeabsorption performance as a core of the tile, and a preparation processthereof.

Technical Solution

In accordance with an aspect of the present invention, the above andother objects can be accomplished by the provision of a tile comprisinga core and a surface layer surrounding the core, wherein an activatedcarbon is contained only in the core and removed from the surface layerby a heat treatment.

The surface layer may contain ash formed by oxidation of an activatedcarbon, and as a result, the surface hardness and strength of the tilemay be improved.

The tile of the present invention may be produced from a compositionwhich comprises 40 to 80% by weight of a loess, 0 to 20% by weight of aclay, 5 to 30% by weight of an activated carbon, and 10 to 30% by weightof water.

It is preferable that the activated carbon is a finely pulverized powderwith a particle size of 0.14 mm (100 mesh) or less in consideration ofits effect on removing formaldehyde.

In accordance with another aspect of the present invention, there isprovided a process for preparing a tile by subjecting the compositioncontaining the activated carbon to a heat treatment.

Specifically, the process comprises the steps of: preparing a drymixture of 40 to 80% by weight of a loess, 0 to 20% by weight of a clay,and 5 to 30% by weight of an activated carbon; adding 10 to 30% byweight of water to the mixture and kneading the wet mixture forextrusion molding; drying the extruded molding at 60 to 100° C. for 40to 70 minutes, and baking the dried molding at 600 to 900° C. for 60minutes or less.

Preferably, the process further comprises the steps of applying a glazeon the dried molding before baking for improving the contaminationresistance of tile. At this time, it is preferable that the glaze has amelting point temperature of 600 to 1,100° C. and contains 30 to 50% byweight of water for increasing the surface porosity.

DESCRIPTION OF DRAWINGS

The above and other objects, features and other advantages of thepresent invention will be more clearly understood from the followingdetailed description taken in conjunction with the accompanyingdrawings, in which:

FIG. 1 is a cross sectional view of a tile according to the presentinvention.

BEST MODE

The present invention will be described in a greater detail withreference to the accompanying drawing and Examples.

FIG. 1 is a cross sectional view of a tile according to the presentinvention. The tile 1 of the present invention comprises a core 10 and asurface layer 20 surrounding the core 10.

The core 10 contains an activated carbon, a loess and/or a clay, and theactivated carbon in the surface layer 20 is removed by a heat treatment.

Activated carbon has a good reactivity such that it is removed by theheat treatment. Therefore, the activated carbon does not exist in thesurface layer 20, but rather the activated carbon is oxidized and existsas ash.

When examining a cross-section of the tile 1 of the present invention,the core 10 and the surface layer 20 are clearly distinguished by theircolors. That is, the surface layer 20 containing the loess and/or clayexhibits yellow ochre, while the core layer 10 containing the activatedcarbon exhibits blackness.

Accordingly, a suitable heat treatment allows the activated carbon toexist only in the core 10, and removes it from the surface layer 20.Thereby, the activated carbon is protected by the surface layer 20 sothat the effect of activated carbon on absorbing formaldehyde can bemaximized. Moreover, due to the ash resulting from the oxidizedactivated carbon in the surface layer 20, the surface hardness andstrength of the tile can be increase.

The process for preparing a tile of the present invention is carried outin the following order.

First, a tile composition is prepared. The tile composition is a drymixture of 40 to 80% by weight of a loess, 0 to 20% by weight of a clay,and 5 to 30% by weight of an activated carbon. The clay may beoptionally added.

It is preferable that each base material is used in a finely pulverizedpowder, in consideration of its effect on removing formaldehyde.Particularly, the activated carbon in a finely pulverized powder havinga particle size of 0.14 mm (100 mesh) or less is preferably used.

Next, 10 to 30% by weight of water is added to the mixture, and the wetmixture is kneaded for extrusion molding.

Subsequently, the extruded green tile molding is dried at 60 to 100° C.for 40 to 70 minutes.

Then, the dried tile molding is baked in a continuous firing furnace ata maximum baking temperature of 600 to 900° C. with the time formaintaining the maximum temperature of 0.5 to 20 minutes, and for thetotal baking time of 60 minutes or less.

In the above process, a glaze can be applied to the tile to increasecontamination resistance, and it is preferable that the glazing processis carried out between the steps of drying and baking. The type of glazeused herein is not particularly limited. However, it is preferable thata glaze has a melting point temperature of about 600 to 1,100° C. andcontains 30 to 50% by weight of water to increase the surface porosity.

Mode for Invention EXAMPLE 1

60 to 80% by weight of a loess, 10 to 20% by weight of an activatedcarbon having a particle size of 0.14 mm or less, and 10 to 30% byweight of water were added, and the mixture was kneaded for extrusionmolding. The molded tile was dried at 60 to 100° C. for 50 minutes andsubjected to a heat treatment at 800° C. for the total baking time of 60minutes to prepare a tile with an activated carbon core.

EXAMPLE 2

A tile was prepared in the same manner as in Example 1, except that aglaze, with a melting point of 1,000° C., containing 50% by weight ofwater was applied onto the dried molded tile between the steps of dryingand baking. The subsequent baking step was carried out in the samemanner as in Example 1.

COMPARATIVE EXAMPLE 1

A loess tile

COMPARATIVE EXAMPLE 2

A charcoal tile

EXPERIMENTAL EXAMPLE

A formaldehyde absorption performance on the tiles of Examples andComparative Examples were evaluated, and the results are presented inTable 1. The formaldehyde absorption amount was measured by the amountof formaldehyde absorbed per 1 g of the tile material.

TABLE 1 Formaldehyde absorption amount (μg/g) Comparative 5.3 Example 1Comparative 5.5 Example 2 Example 1 52

As can be seen from Table 1, the tile according to the present inventionmaximized the formaldehyde absorption performance of the activatedcarbon by adopting the activated carbon-in-core structure. The tile ofthe present invention had excellent formaldehyde absorption amount ofabout 10 times compared with the conventional tile using loess orcharcoal.

According to the present invention, a core of tile contains an activatedcarbon with excellent formaldehyde absorption performance, therebyallowing maximum absorption performance of the activated carbon.Moreover, a surface layer of tile includes ash formed from the oxidizedactivated carbon, so that the surface hardness and strength of the tilemay be increased.

INDUSTRIAL APPLICABILITY

The tile of the present invention can be expected to have a maximumabsorption performance while maintaining the basic physical propertiesof an activated carbon which has excellent formaldehyde absorptionperformance. Also, the oxidized activated carbon forms ash in thesurface of the tile such that a surface binding effect is obtained. As aresult, the surface hardness and strength of the tile can be increased.

Although the preferred embodiments of the present invention have beendisclosed for illustrative purposes, those skilled in the art willappreciate that various modifications, additions and substitutions arepossible, without departing from the scope and spirit of the inventionas disclosed in the accompanying claims.

1. A tile comprising: a core; and a surface layer surrounding the core,wherein an activated carbon is contained only in the core and removedfrom the surface layer by a heat treatment.
 2. The tile according toclaim 1, wherein the surface layer contains ash formed by oxidation ofan activated carbon.
 3. The tile according to claim 1, wherein the tileis produced by the heat treatment of a composition comprising 40 to 80%by weight of a loess, 0 to 20% by weight of a clay, 5 to 30% by weightof an activated carbon, and 10 to 30% by weight of water.
 4. The tileaccording to claim 1, wherein the activated carbon is a finelypulverized powder having a particle size of 0.001 to 0.14 mm.
 5. Aprocess for preparing a tile which comprises the step of subjecting acomposition containing an activated carbon to a heat treatment.
 6. Theprocess according to claim 5, wherein the process comprises the stepsof: preparing a dry mixture of 40 to 80% by weight of a loess, 0 to 20%by weight of a clay, and 5 to 30% by weight of an activated carbon;adding 10 to 30% by weight of water to the mixture, and kneading the wetmixture for extrusion molding; drying the extruded molding at 60 to 100°C. for 40 to 70 minutes; and baking the dried molding at 600 to 900° C.for 1 to 60 minutes.
 7. The process according to claim 6, wherein theprocess further comprises the step of applying a glaze on the driedmolding before baking.
 8. The process according to claim 7, wherein theglaze has a melting point temperature of 600 to 1,100° C. and contains30 to 50% by weight of water.